Indiana State Police Sgt. Stephen Wheeles posted the photo over the weekend. Facebook/Twitter

An Indiana state trooper's tweet about a slowpoke driver has made him an internet sensation.

It all started when Sgt. Stephen Wheeles posted a photo of a car he'd pulled over on Interstate 65 with the admonishment that driving too slow was against the law, just like speeding.

"If you are traveling in the left lane and you have cars backed up behind you, and they are waiting to overtake you or pass you... you are required to move to the right.

"She was just given a warning, but used it as an opportunity to educate her," he wrote. "I don't think she was really clear on what the law in Indiana was, as far as using the left lane."

The state's so-called "slowpoke law" mandates that drivers must move over if the cars behind are traveling at a faster speed. Going too slow in the left lane can cause traffic dangers just as serious as driving too fast, the ordinance says.

I stopped this vehicle today for a left lane violation on I-65. The driver had approximately 20 cars slowed behind her because she would not move back to the right lane.

"The spirit of the law is that since many people drive well above the speed limit, it creates an "accordion effect" as traffic starts backing up behind the slower vehicle. This is where many of our crashes occur on the interstates. It’s all in the name of safety," he tweeted in response to an online question.

His post has been retweeted more than 28,000 times. He also posted the image to his Facebook page, where he's receiving scores of comments.

"You should nationally train other state troopers of this rule. They may have forgotten there is (sic) other violations other than speeding," wrote Rodney Stults.

"You are my hero," posted Tara Videle. "Every day in my commute the left lane is clogged with folks like that. Are they ignorant or stubborn? Just move over please."